Hi because that is what the Bible tells us the exact wording, some people do not understand. The main idea is that we are waiting for something powerful to happen, a display of divine power. We have other passages in the Bile to tell us this "display" will herald truth as in the arrival of the Second Coming of Christ which is foretold in the Bible.
This is important information because God is invisible, and the Kingdom's arrival cannot be displayed for the physical eye to see. We never really expect to see buildings that acknowledge the Kingdom's exist but condition that express the operation of power over the earth's natural elements. The total display will continue until the new heavens and the new earth are established to the naked eye for all to see.